An American Serial Killer in London
by lovethefandom
Summary: * Sherlock - The Mentalist : Crossover Prompt * I really, really, really want a Sherlock/The Mentalist crossover. How it happens is completely up to you. Patrick finds himself in London, investigating what appears to be a Red John case, with a lot of help from Sherlock and John. {Rating for Future Chapters}


* Sherlock - The Mentalist : Crossover Prompt *

 _I really, really, really want a Sherlock/The Mentalist crossover. How it happens is completely up to you. Patrick finds himself in London, investigating what appears to be a Red John case, with a lot of help from Sherlock and John._

09:15, Tuesday, California

Patrick Jane sat at his kitchen table, frozen in place. A piece of paper shook slightly between his quivering fingers, his gaze so intense and yet he could barely keep it focused on the words he was trying to read, instead his eyes kept returning to that image. That familiar shape, the one that bore into his nightmares and left him with an intense, burning feeling of dread. He swallowed hard.

There was no time. There was no choice. He needed to see this for himself. He needed to know.

His fingers released the paper as he pushed himself sharply to his feet, the force of it knocking his chair back at such an angle that it toppled. He abandoned it where it had clattered against the stone tiles. There were few thoughts that he could allow to occupy his mind at this particular moment, and the chair was not one of them.

He didn't move with his usual grace, his steps were clumsy with their urgency as he surged his way forward and snatched his cell phone up from the workbench. It didn't take more than a moment to hold down the number one on the keypad, bringing Lisbon's name flashing onto the screen from the speed dial.

There was a brief moment of pause as she picked up the call and apparently offered some typical greetings.

"I will be on leave for a while, Lisbon," he interrupted, controlling his voice so as not to give away anything that might worry her. There was another pause.

"I'm not sure, at least a week. Maybe two," he continued, though finding it increasingly difficult to prevent himself from hurrying her along with her idle small talk.

"Teresa," he spoke soothingly, addressing her by her given name the way he only did when he needed to be sure she was listening. He knew it got her attention, particularly when spoken in his softer tones. "I'm taking some time off, not running away from home. You can call me if you miss me."

He couldn't help the smirk that crossed his features as he heard the familiar 'go screw yourself' that he had decided was as close as she would ever come to admitting that she liked him.

He allowed the call to end there, before heading up the stairs to his room, taking them two at a time and quickly collecting the items he felt he would need during his time away, in the end all he pulled together were an assortment of clothes and a large stack of case files. He looked to the drawer where he kept his small handgun and considered it, but with airport security being what it was it wasn't worth the trouble that would be involved in transporting it.

15:32, Tuesday, London

Sherlock gazed at the photo, still scowling, a smiley face - what was the significance of that? Why a smiley face? And in the victim's blood no less. It reminded him of something, something of which he was vaguely aware of hearing before, of dismissing. Something he had once considered unimportant and cast aside for the benefit of more meaningful information, no matter, he would figure this out.

He closed the image, returning his mobile to his pocket as the taxi stopped and the driver announced that they had reached the destination. It was perhaps the most interesting case he had been offered in some time, the only real irritation here was that there was a distinct lack of his doctor companion; John had agreed to take a late shift at the clinic. Despite the fact Sherlock had texted him a number of times to request that he return to assist with the investigation, John still failed to text back or show up.

And so it was that the young man stalked grumpily towards the crimescene, picking the familiar figure of Lestrade from the small crowd of people that stood outside the small flat.

"Good afternoon, Detective Inspector," he greeted curtly, letting himself in through the open door and following the hallway to the ground floor flat's door. The door had remained open, and as soon as he stepped through it there it was; the image that had been on his phone; the face.

The killer had painted it there, large across an otherwise bare wall, the fading of the wallpaper suggested that he had moved something from the center of the wall to do it. He had used his own fingers, likely gloved; it would take a whole new level of psychopath to do so with an ungloved hand, he had drawn the circle clockwise then added the eyes and mouth. He refreshed the blood on his fingers heavily for each line, it hadn't been necessary for the face to show to do this. Two dips in the blood would have been ample, but he had opted to do so four times, laying the blood so heavily on the wall that it had dribbled down the wall. The imperfection of it was somehow irritating.

"They call him Red John," Lestrade informed him from the doorway as Sherlock turned his attention to the body.

A young woman, naked but with torn bedsheets shifted to conceal her more intimate places. Her flesh had been torn in several places, the amount of bleeding and clotting suggested that this had been the cause of death, but without his doctor here to provide him with that sort of information he couldn't be quite sure.

"They?" questioned Sherlock, leaning over the body to inspect her fingers more closely, his gaze trailing along her arms and shoulders and examining her neck.

"The Americans," Lestrade answered, giving the brief pause that he knew would be needed to Sherlock to voice his heavy sigh. "This fits the M.O. of a serial killer they have been following for years. Red John."

"Have them email me the files," Sherlock instructed, his gaze flickering up from her neck to examing her facial features.

"There's someone I need to introduce you to," Lestrade told him, the irritation in his voice inexplicably rising. "This is Mr. Patrick Jane. He's a consultant with the CBI and I'm told has been following the Red John cases closer than anyone."

This piqued Sherlock's interest at once, he righted himself to look toward the door. There, at the side of the Detective Inspector, was a middle aged man, his blonde hair was unkempt, his three piece suit buttoned but dishevelled. His face was pale, his eyes not looking at Sherlock, but at the face that had been emblazened on the wall, before he dragged the light grey focus of his eyes towards the body, and then at last to Sherlock.

"Under some circumstances I might have accused the man who follows such a successful serial killer closely for so many years to be a suspect, there's a certain ironic thrill in investigating crimes you've committed, is there not?" Sherlock opened conversationally, flashing one of his typically false but charming smiles in the American's direction. "However, were he here I am sure that my companion would say it is in poor taste to accuse a victim's family of being the killer. And it does so make a refreshing change to see one hunting down revenge quite so passionately."

There was, as expected, a brief moment of stunned silence from Lestrade, though he certainly should have expected this much at least - and had he not known that the Mr. Jane he had introduced had a deeply personal connection to this particular crime then Sherlock could only feel a slight concern for what sort of checks Scotland Yard were actually performing before allowing consultants to join them on their cases.

He felt the dread, as soon as he arrived on the street of the crime scene and stepped out of the taxi. There wasn't much of an opportunity to observe his surroundings, Lisbon was still griping in his ear.

"You better tell me Jane, or so help me God I'll have you removed from the investigation," she snarled, clearly her temper hadn't been improved by his previous good humoured jibes.

"He sent a note," Jane relented at last. Her silence on the other end of the call was tense and long.

"Jane, if he baited you there-" if she was trying to hide the intense concern in her voice then she was failing terribly.

"Stop worrying Lisbon, what would he even be doing in England? It's probably just another copy-cat, I'll take a look, call you and be home before you know it," he put great effort into offering his most soothing and reasuring voice, but it was obvious from her silence that she wasn't too impressed with it, so he ended the call there and made his way towards the apartment building that seemed to be the source of all the interest on the street.

Inside the apartment it was all pretty much as Jane had expected it would be, but being right didn't make him happy this time. He was escorted into the building by a friendly enough Detective Inspector, who briefly mentioned that he had spoke with Lisbon regarding allowing the consultant to join on the case.

"We have a consultant ourselves, from what your boss told me about you I think you'll get along just fine," he conversed, in a manner that was strangely conversational considering the nature of their meeting. He carried the same sort of noncholance towards murder scenes as any of the CBI homicide unit, but without giving him the seriousness that his usual team would when Red John was involved.

His eyes darted to the face as soon as he walked into the room, the Detective Inspector began to converse with a strange, tall, gangly sort of man who was inspecting the victim very closely. But all Jane could do was stare at that face; The Red John Smiley Face. He'd recognise it anywhere, even from the other side of the room, even with his eyes strained with tiredness from the flight, he knew that this was real.

He was too absorbed, he hadn't heard it when D.I. Lestrade had introduced him to the strange British consultant. But when he did turn his attention to the gangly man he was surprised. He had thought of stepping forward and offering his hand to provide the more typical greeting for two grown men, but he withdrew it. In little more than a heartbeat the stranger had made several deductions about Jane, which he prided himself on announcing out loud and with confidence.

The Detective Inspector looked at him as though to urge him to deny the claims that had just been made, however Jane could only smirk, finding himself strangely impressed.

"Refreshing?" he asked cheerfully, even he finding his California accent to be somewhat out of place here. "Is that what we call it when we find a sociopath investigating murders, rather than committing them?" he questioned, his brow ever so slightly raised.

The pair watched one another for a long moment, as though some silent, inconceivable battle were being fought, then Jane smiled, allowing his gaze to shift away. A sociopath indeed; he found the gangly man to be completely unphased by the prolongued eye contact.

"This is Mr. Sherlock Holmes, my consultant on a number of cases," Detective Inspector Lestrade explained when the tension in the room had dropped a little.

"Sherlock, unique. Is that a British name?" Jane questioned lightly, beginning to settle into his usual activities he began to stroll into the room, his gaze flickering over the furniture and decór. He couldn't help but think, looking around him, that the English had very tacky tastes when it came to their home furnishings.

"Who's apartment is this?" he asked, turning his head to face Lestrade one more, his brow quirked inquisitively.

"Well, it'll be her flat, won't it?" the Detective Inspector answered as though suspecting that this were a trick question.

"I thought you were a Detective Inspector?" Jane questioned, a slight hint of amusement to his voice, of course he caught the way the Inspector's face tightened as though to withold a groan he was eager to voice.

"You'll have to excuse Lestrade," Sherlock interjected from where he stood still looking at the victim. "The most obvious of details are frequently lost on him," his voice held no particular amusement, but rather a dispassionate tone; he wasn't making fun of the Detective Inspector, he was completely certain of his accusation.

"Who else's could it be? She was found in this flat, no one else is here. It does sort of suggest that this is her flat," he insisted.

"Except that there are no photos; a young woman probably early twenties, living in the city alone she would have family photos or friends, but there's nothing. No TV, no laptop, not even a stereo; when was the last time you met a twenty-something young woman who had no tech at home?" Jane presented his point smoothly, he explained his reasoning quickly and without condension. He could tell from the way the Detective Inspector watched him when he spoke and flickered his gaze briefly to Mr. Holmes that his new colleague did not have quite the same approach to such matters.

"Well then Mr. Jane," Sherlock straightened himself up and adjusted the collar of his long coat slightly. "I believe you will be requiring lodgings. I would very much like to discuss this Red John fellow further, would you care to join me at Baker Street?" He asked, his voice showing a little of something that might be akin to interest or excitement. One thing that Jane couldn't quite shake was the politeness of it, the almost intense formality of the words and phrases he selected, though Jane guessed that this was in an attempt to emphasise his own intelligence.

"Wait, what about the case. Aren't you going to tell me what you've got?" Lestrade growled at Sherlock, apparently frustrated at having been insulted and then forgotten. "It's a copy-cat right? What would an American serial killer be doing in London?" He questioned more urgently.

"Do be careful Lestrade, or John will have us suffer another such abysmal title for this case," he groaned, the way his tone had changed slightly did not escape Jane's notice. Sherlock was amused, feigning annoyance, he didn't seem like the type to feign emotions without a purpose, and yet as soon as he discussed this 'John' person he had done exactly that. Jane smirked.

"Sherlock!" Lestrade barked and though the sudden and sharp sound of his voice had made Jane jump ever so slightly with the surprise of it the gangly consultant didn't even bat an eye, instead he just continued to watch the Detective Inspector with a completely level gaze.

"Oh it's real," Sherlock purred at last, now offering no veil to his excitement. "This is Red John, that much is obvious, and I'll hazard a guess that it is completely fitting to his normal M.O. The victim was disabled with a tazer and then restrained on the bed. He takes his time killing her, he waited for her to wake up before he started cutting and didn't stop until she was dead. He staged the scene afterwards, with a lot of care and precision. I do believe he's looking for attention," Sherlock deduced, with a pointed look in Jane's direction.


End file.
